Dash-pot buffer.



A. T. BROWN.

y DASH POT BUFFER. APPLICATION man APR. 2. 1911.

1-,267,@26. A Patented May28, 1918.

- warren era-.ree

ALFRED fr. BROWN, or CINCINNATI, omo, AssreNoR To THR WARNER ELRvA'roR\-1vrref. COMPANY, or CINCINNATIEVCHIC, AkCoRroReTroN or CHIC,

DASH-'POT BUFFER;

Specification of Letters Patent. Patnted May 28,4 ,19.18; l

Applicationfledpril2, 191,7. v SeriaLNo. 159,320.

Toall 207mm Vraag/ concernuseful Improvement. in Dash-l3ot Buffers,

olfk which .A they; following specification is' a` full disclosure, 'i

Mycinvention rrelates .to ka heavy. duty bufferfadapted to eleyator usage and theflike.

tOebeA placedV near the end ofthe pathI of trayel of tai.pioiiderousbody, to. cushion.they

inalinoyenient vand bringthe bodyfto .rest without shock-,011 jar.;y i

Asis.eoingqnQni in. de vices v`of kthis character. a cylinder and piston arrangementis'ernployed, the,resistancel agency beingr combined i tension." mechanism u and the Huid to be Vdisplacedfreni one sideto the other of the moing .piston by passing; around and through said piston. during its ,reciprocating movements.

` The objectsof thedmzention are ,toppovid e themaxi 1num resistance With ,a com paratively Y short piston, lstrueture, to elfe@- tually guide the spring; toproVide structuresand arrangements' controlling the oil displacement fiowunder `the influence of the nioiringpistony and to ,constitute a. buffer stron g; enough foi: this Yheayy duty, durable, efficient. automatic and wholly reliable7` so as .tol insuresafety as .well yas .superior buff4 ing,v function.

The features of the nventionwill be more fully set forth in the descripti on of the ac-, ctn/npanyingjrdrawings,V forming a part of upswardlyiiared-, this tapergcylinder portion 4 termignatin g at line, ee, representing the upperor normal,pistongposition. Aboveline the cylinder 1s widened outto constitute an oil displacementeharnber 6,;haying,

the Cylinder4 head ,7 oriiiced for thel piston rod., The piston; rod y8 is hollow andthe pisf ton, 9y lits the circumferential cylinder portion Q and has ayalve 10, heldnorrnally, closedfwhenethe piston drops by means of valve stems 11 Aand coil Springs Al2, and opening4 when, the v pist0n retracts ton flow oil from,A the displaceine11tchamb'en back into the ydash-pot orcylindQr- The fhollow rod S extendsthrough the piston, thus Corninunicating with; theV holder 'throughy the ajrestricted coiniiiunieation with; the holder, wherebyi the oil offers'resistance'to thewpis-y ton movement in the directionfof spring compression.

To ,center the piston, guide it andenable tension means .to he effectual, Combined 'with the oil, resistance,- 1 provide Jthe following inetruinentalities A concentric guide rod oiwpostlgfis secured in the base 1 and it passes upwardly centrally through the piston and jhollow pistou rod. terminating, preferably., just aboie line 2 3, iii-,the lower end of thefdis-v placement chamber.

Also, preferably, auguidesleeve livwprof jects eoncentrically downwardly freni the Cylindechead 7, terminating nearthe line {e2-'2, andornis an external guideQfonthe hollow piston rocha rod 13 fixed to thefbase projects intothe hollowpistonrod and 'forms an internal guide forthefspring 15, which housed. within the piston rod as the .piston descends in its cylinder. This coil spring vextends from basel tothe screw `thread adjustable plug 16 in theupper end of the h oln lCwpiston-rod.. Above plug` l isprefe'rably7 a spring` bumper 17 forushioningthe initial'oontact oii elevator member 18. In order to return to the ,cylinder-,fthe oil which worksI up between the interior of the guide Sleeve 14 and the exterior of the hollow piston rod.'8, I ,provideoriices 19 in the upper end of this guido sleeve. lilith the biiiiier ready for operation. and oil in the cylinder portions 2 and 4f (Fig. the meinberto be cushioned (i. e. elevator or weight) Vengages the end of the piston rod and forces the piston downwardly into the tapering portion of the cylinder, simultaneouslycompressing. the piston rod spring and displacing the oil around the piston periphery, whence itr escapes into the upper chamber 6. Of course the oil will offer less resistance at the beginning of the piston movement because the oil will escape more freely around the piston at the larger diameter portion of the taper cylinder bore, gradually escaping with more diliiculty as the piston descends, and so operating to rapidly increase the resistance to provide any desired degree of cushioning or braking force in a relatively short dimension of piston or elevator inoveinentt lhen the piston reaches line cri-a3 where the cylinder circumferentially lits the piston, the greatest resistance will be odered. The oil being forced upwardly into the space lbetween the post 13 and the hollow piston rod and around the coil spring, will also work in between the guide sleeve and piston-rod, thus thoroughly oiling all the moving elements, rendering the cushioning eect smooth and uniform.

When the piston has reached the end of itsbuder movement, the coil spring is not fully compressed, coil on coil. lhe coil spring is supported and guided throughout the length, and a compact cylinder and piston are 'provided with a lenoth of' travel adequate to give eflicient butler operation... lfVlien the elevator or weight is raised, the spring raises the piston, the oil flowing bach: through the. piston valves into the dash-pot cylinder portions 2 ande. t a

Having described iny invention, l claim l. In a device of the class described, fluid holder having a cylindrical portion at one end and a conical portion communicating therewith, a piston reciprocal therein, a hollow piston rod communicating through the piston with the fluid holder, a concentric guide post secured within. the holder and passing through the piston into the hollow rod, a coil spring Within the piston rod surrounding said guide post, and adapted to move the piston in one direction, an external guide sleeve in the upper portion oi' the holder for the piston rod, and means for freely flowing the fluid i'roin one side oi' the piston to the other during the spring actuated piston stroke.

ln a device of lthe class described, a fluid holder having a cylindrical and a conical portion, a piston iitting the circumferential portion, a hollow piston rod, a guide post secured to the holder and extending through the piston into the hollow rod, a coil spring surrounding said post, extendmerece ing through the rod and adapted to more the piston in one direction, and means causing the fluid to otter resistance to the piston movement when the spring is being coin pressed, and to flow ,freely from one side of the piston to the other when the piston is spring actuated. V i

3. ln a device of theclass described, a fluid holder, a piston, a hollow piston rod communicating with the holder through the piston, a coil spring in the rod extending from the base of the holder to the ytop of the rod adapted yfor moving the piston in one direction, and means providing a restricted fluid escape during the compressing movement of the piston, and for freely returning `the fluid to normal position in ythe .holdery i during the spring actuated movement of the piston.

d. ln a device of the `class described, a duid holder having a cylindrical portion at one end and a conical portion communicating therewith, a piston reciprocal therein, a hollow piston rod.communicating through the piston with the fluid holder, a coil spring with in the piston rod adapted to move the f piston in one direction, and means for freely iiowing the duid from one side of the piston to the other during the spring actuated piston stroke.

5. A combined fluid and spring resistance buihng device comprising a fluid cylinder, reciprocating piston, and hollow piston rod, a spring for moving the piston in one direction, there being restricted fluid communication around the piston and through the piston into the'hollow piston rod, and means providing a n relatiifely unrestricted return passage `for the fluid when the piston is spring actuated.

6. A combined fluid and spring resista-nce boiling device comprising a duid cylinder and a reciprocating piston, a hollow piston rod communicating with the cylinder through the piston, a guidepost in the cylinder extending through the piston into the hollow piston rod, a spring centered on said post and extending from the end of the cylinder to the other endof the hollow piston rod, there being restricted Huid communication from one side of the pistonA tothe other during a portion of the piston springl conipressing stroke, and means providing a relatively unrestricted return for `the fluid when the piston is spring actuated.

7. Ina device'of the class described, a cylinder, a piston reciprocal therein, rvthe cylinder having auid overflow portion projected Y incler` a piston reciprocal therein, a hollow my name, as attested by the two Subscribing piston rod, a guide-post n the cylinder eX- witnesses. tending into the hollow piston rod, and a Coil spring supported on the guide post and ex- 5 tended into the piston rofl for moving the Vtnesses:

piston to normal position. M. SMITH,

In witness whereof, I hereunto subscribe L. BUCK.

ALFRED T. BROWN.

copies of this patent may be obtained'for fxve cents each, by addressing the Commissioner o! Iatentl,

Wnshington, D. G. 

